纳滤工艺深度处理焦化废水的中试研究

Pilot study on the advanced treatment of coking wastewater by NF process

以焦化废水为研究对象,考察了取消超滤预处理系统后,纳滤处理系统对该类废水污染物的处理效果。结果表明:纳滤工艺可直接应用于焦化废水的深度处理,COD去除率稳定在70%以上,出水COD维持在45mg/L以下;对氨氮的去除率可达50%以上;对总硬度的脱除率达96%以上,出水硬度维持在3.5 mg/L左右,各项水质均优于循环冷却水要求。虽然单独纳滤工艺稳定运行周期相对双膜工艺较短,但两种工艺的污染差异可通过化学清洗加以消除。

Using coking wastewater as research target,after the cancellation of UF pretreatment system,the treatment effect of NF systems on this kind of wastewater pollutants has been investigated. The results show that the NF process can be applied to the advanced treatment of coking wastewater directly,and its COD removing rate stays at above 70%,effluent COD maintains at 45% or less,SO4＋-N removing rate is above 50%,total hardness removing rate reaches 96% or more,the effluent hardness maintains at about 3.5 mg/L. The water quality of every item is superior to the requirements for circulating cooling water. Although the stable operation period of single NF process is shorter than that of double membrane process,the pollution gap of these two kinds of processes can be eliminated by chemical cleaning.